:root{
  --bg:#ffffff; --bg-alt:#f5f8ff; --ink:#0f172a; --muted:#64748b;
  --line:#e7edf6; --brand:#2f6bff; --brand-d:#1f50d6; --brand-soft:#eaf1ff;
  --accent:#10b981; --radius:16px; --shadow:0 6px 24px rgba(20,40,90,.07);
  --shadow-lg:0 14px 40px rgba(20,40,90,.12);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0; font-family:-apple-system,"PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  color:var(--ink); background:var(--bg); font-size:15px; line-height:1.65;
  -webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none}
.container{max-width:1140px;margin:0 auto;padding:0 20px}
.container.narrow{max-width:840px}

/* 按钮 */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;
  padding:10px 18px;border-radius:10px;font-size:14px;font-weight:600;cursor:pointer;
  border:1px solid transparent;transition:.15s;white-space:nowrap}
.btn.primary{background:var(--brand);color:#fff}
.btn.primary:hover{background:var(--brand-d)}
.btn.outline{background:#fff;border-color:var(--line);color:var(--ink)}
.btn.outline:hover{border-color:var(--brand);color:var(--brand)}
.btn.ghost{background:transparent;color:var(--ink)}
.btn.ghost:hover{color:var(--brand)}
.btn.lg{padding:13px 26px;font-size:15px}
.btn.full{width:100%}

/* 导航 */
.nav{position:sticky;top:0;z-index:20;background:rgba(255,255,255,.85);
  backdrop-filter:saturate(180%) blur(10px);border-bottom:1px solid var(--line)}
.nav-inner{display:flex;align-items:center;justify-content:space-between;height:64px}
.logo{display:flex;align-items:center;gap:8px;font-weight:800;font-size:18px;color:var(--brand)}
.logo em{font-style:normal;color:var(--muted);font-weight:600;font-size:14px}
.logo img.logo-img{width:28px;height:31px;display:block}
.nav-links{display:flex;gap:26px;font-size:14px;color:var(--muted)}
.nav-links a:hover{color:var(--brand)}
.nav-cta{display:flex;gap:10px;align-items:center}

/* Hero：左文右图 */
.hero{position:relative;overflow:hidden;background:
   radial-gradient(1200px 600px at 80% -10%, #e8f0ff 0%, rgba(232,240,255,0) 60%),
   radial-gradient(900px 500px at 0% 10%, #eaf6ff 0%, rgba(234,246,255,0) 55%),
   linear-gradient(180deg,#f7faff 0%,#ffffff 100%);
   padding:56px 0 64px}
.hero-glow{position:absolute;width:520px;height:520px;border-radius:50%;
  background:radial-gradient(circle, rgba(47,107,255,.16) 0%, rgba(47,107,255,0) 70%);
  top:-120px;right:-80px;pointer-events:none}
.hero-grid{position:absolute;inset:0;pointer-events:none;opacity:.5;
  background-image:linear-gradient(#e7edf6 1px,transparent 1px),linear-gradient(90deg,#e7edf6 1px,transparent 1px);
  background-size:46px 46px;
  -webkit-mask-image:radial-gradient(circle at 70% 30%,#000 0%,transparent 75%);
          mask-image:radial-gradient(circle at 70% 30%,#000 0%,transparent 75%)}
.hero-inner{position:relative;display:grid;grid-template-columns:1.05fr .95fr;
  gap:40px;align-items:center}
.hero-text{max-width:560px}
.badge-tag{display:inline-block;background:var(--brand-soft);color:var(--brand);
  font-size:13px;font-weight:600;padding:6px 14px;border-radius:99px;margin-bottom:18px}
.hero h1{font-size:44px;line-height:1.22;margin:0 0 18px;font-weight:800;letter-spacing:-.6px;color:var(--ink)}
.hero h1 .hl{color:var(--brand)}
.sub{color:#475569;font-size:16.5px;margin:0 0 26px;max-width:520px}
.sub b{color:var(--ink)}
.hero-actions{display:flex;gap:14px;flex-wrap:wrap}
.trust{display:flex;gap:18px;flex-wrap:wrap;margin-top:30px;color:var(--muted);font-size:13.5px;font-weight:600}
.trust .dot{display:inline-block;width:8px;height:8px;border-radius:50%;margin-right:6px;vertical-align:middle}
.trust .dot.ok{background:var(--accent)}
.hero-art{position:relative;min-height:520px;display:flex;align-items:center;justify-content:center;max-width:620px;margin:0 auto}
.hero-art svg{max-width:620px;max-height:520px;width:100%;height:100%}

/* 数据条 */
.stats-band{background:linear-gradient(135deg,#2f6bff,#5b8bff);color:#fff;padding:30px 0}
.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:18px;text-align:center}
.stat-num{font-size:40px;font-weight:900;line-height:1}
.stat-label{font-size:14px;margin-top:8px;opacity:.92}

/* 区块 */
.section{padding:68px 0}
.section.alt{background:var(--bg-alt)}
.sec-title{text-align:center;font-size:30px;font-weight:800;margin:0 0 10px;color:var(--ink)}
.sec-sub{text-align:center;color:var(--muted);max-width:680px;margin:0 auto 40px;font-size:15px}

/* 优势网格 */
.grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.grid-4{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}
.feat{background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:24px;box-shadow:var(--shadow);transition:.15s}
.feat:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg)}
.feat-ic{width:46px;height:46px;border-radius:12px;display:flex;align-items:center;
  justify-content:center;color:#fff;margin-bottom:14px}
.bg1{background:#2f6bff}.bg2{background:#10b981}.bg3{background:#f59e0b}
.bg4{background:#8b5cf6}.bg5{background:#ef4444}.bg6{background:#0ea5e9}
.feat h3{margin:0 0 8px;font-size:17px}
.feat p{margin:0;color:var(--muted);font-size:14px}
.feat code{background:var(--bg-alt);padding:1px 6px;border-radius:5px;font-size:12px}

/* 工作原理：左右分栏 */
.split-row{display:grid;grid-template-columns:1fr 1fr;gap:48px;align-items:center;
  padding:26px 0;border-top:1px solid var(--line)}
.split-row:first-of-type{border-top:0}
.split-row.reverse{direction:rtl}
.split-row.reverse > *{direction:ltr}
.split-text{max-width:440px}
.step-n{width:36px;height:36px;border-radius:50%;background:var(--brand);color:#fff;
  display:flex;align-items:center;justify-content:center;font-weight:800;margin-bottom:14px;font-size:16px}
.split-text h3{margin:0 0 10px;font-size:20px;color:var(--ink)}
.split-text p{margin:0;color:var(--muted);font-size:15px}
.split-art{background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:18px;box-shadow:var(--shadow);min-height:220px;display:flex;align-items:center;justify-content:center}

/* 套餐 */
.plan{background:#fff;border:1px solid var(--line);border-radius:var(--radius);
  padding:22px 16px;box-shadow:var(--shadow);position:relative;display:flex;flex-direction:column}
.plan.best{border-color:var(--brand);box-shadow:var(--shadow-lg)}
.p-flag{position:absolute;top:-12px;left:50%;transform:translateX(-50%);
  background:var(--brand);color:#fff;font-size:12px;font-weight:700;padding:4px 14px;border-radius:99px}
.p-name{font-size:17px;font-weight:800;text-align:center}
.p-price{text-align:center;font-size:30px;font-weight:900;margin:10px 0 14px;color:var(--brand)}
.p-price small{font-size:13px;color:var(--muted);font-weight:500}
.plan ul{list-style:none;padding:0;margin:0 0 18px;flex:1}
.plan li{padding:6px 0 6px 22px;position:relative;color:var(--muted);font-size:13px}
.plan li::before{content:"✓";position:absolute;left:0;color:var(--accent);font-weight:800}

/* FAQ */
.faq{background:#fff;border:1px solid var(--line);border-radius:12px;padding:4px 18px;margin-bottom:12px}
.faq summary{cursor:pointer;font-weight:600;padding:14px 0;list-style:none;position:relative}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";position:absolute;right:0;color:var(--brand);font-size:20px;font-weight:700}
.faq[open] summary::after{content:"−"}
.faq p{margin:0 0 14px;color:var(--muted);font-size:14px}
.faq strong{color:var(--ink)}

.callout{margin-top:32px;background:#fff;border:1px solid var(--line);border-left:4px solid var(--brand);
  border-radius:12px;padding:18px 20px;color:var(--muted);font-size:14px}
.callout b{color:var(--ink)}
.callout strong{color:var(--brand)}

/* 结尾 CTA */
.cta-band{background:linear-gradient(135deg,#2f6bff,#5b8bff);color:#fff;text-align:center;padding:60px 0}
.cta-band h2{margin:0 0 10px;font-size:28px}
.cta-band p{margin:0 0 22px;opacity:.92}
.cta-band .btn.primary{background:#fff;color:var(--brand)}
.cta-band .btn.primary:hover{background:#eef4ff}

/* 页脚 */
.foot{border-top:1px solid var(--line);padding:22px 0;background:#fff}
.foot-inner{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:8px;font-size:13px}
.foot .muted{color:var(--muted)}

@media (max-width:1100px){
  .grid-4{grid-template-columns:repeat(2,1fr)}
}
@media (max-width:860px){
  .grid-3{grid-template-columns:1fr}
  .grid-4{grid-template-columns:1fr}
  .nav-links{display:none}
  .hero-inner{grid-template-columns:1fr;gap:24px}
  .hero h1{font-size:30px}
  .hero-art{min-height:300px}
  .hero-art svg{max-height:300px}
  .stats{grid-template-columns:repeat(2,1fr);gap:22px}
  .split-row{grid-template-columns:1fr;gap:18px}
  .split-row.reverse{direction:ltr}
  .step-arrow{transform:rotate(90deg)}
}